1. Field
An aspect of the present invention relates to a fuel cell and a manufacturing method thereof.
2. Description of the Related Art
Fuel cells are a high-efficiency, clean generation technology for directly converting hydrogen and oxygen into electric energy through an electrochemical reaction. Here, the hydrogen is contained in a hydrocarbon-based material such as natural gas, coal gas, or methanol, and the oxygen is contained in the air. Such fuel cells are classified into alkaline fuel cells, phosphoric acid fuel cells, molten carbonate fuel cells, solid oxide fuel cells, and polymer electrolyte membrane fuel cells, depending on the type of electrolyte used.
Among these fuel cells, the solid oxide fuel cell is a fuel cell operated at a high temperature of about 600 to 1000° C. Solid oxide fuel cells are widely used because the position of the electrolyte is relatively easily controlled, there is little or no concern about the exhaustion of fuel, and the lifetime of the material is long, compared with various types of conventional fuel cells.
In solid oxide fuel cells, the inside and outside of a unit cell are different electrodes from each other, and therefore, different kinds of fuels are supplied to the electrodes, respectively. When a leak occurs in a sealing portion due to the lack of sealing between the unit cell and a cell coupling member, the temperature of the cell is increased by mixing and igniting both the fuels at a high temperature, and accordingly, the deterioration of the cell is accelerated. Therefore, the durability of the solid oxide fuel cell may be reduced.